diff options
Diffstat (limited to 'udevd.c')
| -rw-r--r-- | udevd.c | 30 |
1 files changed, 28 insertions, 2 deletions
@@ -222,6 +222,11 @@ static void handle_msg(int sock) { struct hotplug_msg *msg; int retval; + struct msghdr smsg; + struct cmsghdr *cmsg; + struct iovec iov; + struct ucred *cred; + char cred_msg[CMSG_SPACE(sizeof(struct ucred))]; msg = msg_create(); if (msg == NULL) { @@ -229,13 +234,30 @@ static void handle_msg(int sock) return; } - retval = recv(sock, msg, sizeof(struct hotplug_msg), 0); + iov.iov_base = msg; + iov.iov_len = sizeof(struct hotplug_msg); + + memset(&smsg, 0x00, sizeof(struct msghdr)); + smsg.msg_iov = &iov; + smsg.msg_iovlen = 1; + smsg.msg_control = cred_msg; + smsg.msg_controllen = sizeof(cred_msg); + + retval = recvmsg(sock, &smsg, 0); if (retval < 0) { if (errno != EINTR) dbg("unable to receive message"); return; } - + cmsg = CMSG_FIRSTHDR(&smsg); + cred = (struct ucred *) CMSG_DATA(cmsg); + + if (cred->uid != 0) { + dbg("sender uid=%i, message ignored", cred->uid); + free(msg); + return; + } + if (strncmp(msg->magic, UDEV_MAGIC, sizeof(UDEV_MAGIC)) != 0 ) { dbg("message magic '%s' doesn't match, ignore it", msg->magic); free(msg); @@ -289,6 +311,7 @@ int main(int argc, char *argv[]) struct sockaddr_un saddr; socklen_t addrlen; int retval; + const int on = 1; struct sigaction act; init_logging("udevd"); @@ -324,6 +347,9 @@ int main(int argc, char *argv[]) goto exit; } + /* enable receiving of the sender credentials */ + setsockopt(ssock, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on)); + while (1) { handle_msg(ssock); |